(FORTUNE Magazine) – It starts with a dazzling light like a halo, a radiant aura. Without warning, ordinary objects--your phone, your keyboard--take on a preternatural, twinkling glow. For migraine-headache sufferers, the light portends blinding pain in the brain, replete with nausea, weakness, and an excruciating sensitivity to sound.

The Journal of the American Medical Association reports that about 11 million Americans suffer "moderate to severe disability" due to migraines. Estimated cost to U.S. business in lost productivity: $6 billion to $8 billion a year. Cost to headache victims: jobs, promotions--even careers.

"I used to think that people who could be incapacitated by a headache must be real wussies," says Ron Weiss, a production control engineer in Whitehall, Pennsylvania, "but that was before I started getting them." Charles Dombeck, an information systems manager in St. Louis, relies partly on a prescription drug called Imitrex (generic name: sumatriptan succinate) to nip his migraines in the bud: "Otherwise I have to go home from work, close the drapes, and be alone in the dark with the pain."

Imitrex, made by British pharmaceutical powerhouse Glaxo Wellcome and introduced in the U.S. in 1993, can stop a migraine in full swing. Up to now sufferers had to inject it. The good news: In September, "Suma," as its fans have nicknamed it (Brave New World, anyone?), becomes available in the U.S. in tablet form. Says Dr. Seymour Diamond, executive director of the National Headache Foundation in Chicago: "You'd be surprised how many people are afraid to give themselves a shot." No, we wouldn't, actually.

More help is on the way. Abbott Laboratories expects to get the FDA's go-ahead to market Depakote (generic name: divalproex sodium), which has been shown to stop migraines before they start. Depakote is now used to treat epilepsy and manic depression. Take it daily and, lucky you, you may never have to leave work again.

- Anne B. Fisher